Hidden Roots, Tree Fungi and Lidar Canopy Maps

This edition starts below the street. New research describes a hidden second root system in plants, a Boston University report shows that cutting up forests disrupts the bond between trees and fungi, and cities are mapping canopy with lidar. On the money side, West Liberty University won a $1.5 million urban forestry grant while federal funding retractions push tree-planting programs to adapt.

Photo by Surprising_Media on Pixabay

The hidden second root system

Recent studies describe a hidden secondary root system in plants that sits beneath the primary roots and plays a part in carbon sequestration. It interacts more extensively with soil microbes and organic matter, so supporting it in cities could improve both tree performance and soil health. Ground penetrating radar combined with machine learning is already being used to map these complex root architectures.

The same underground network is easy to damage. Compacted soil restricts root growth and leaves shallower root systems that cope poorly with stress. It also disrupts mycorrhizae, the partnerships between roots and fungi that supply nutrients and water. Boston University's The Brink reported that cutting up forests breaks this essential bond between trees and fungi. In cities, aeration and added organic matter can restore healthier soil structure.

Mapping canopy from above

A study center in Laredo, Texas is using lidar to map tree canopy, a method that builds high-resolution 3D models of canopy structure and biomass. Purdue University's AI urban tree monitoring initiative takes the image-based route, and Geo Week News described how geospatial technology helps planners protect and expand urban forests. Twin Cities suburbs are using technology to spot troubled trees, and UAB shows how a campus can protect a nationally recognized urban forest. Satellites add continuous observation of canopy cover and tree health, and digital inventories keep the records current.

Want to see how hot and green your own area looks from space? Our free Land Surface Temperature tool returns a land surface temperature and NDVI report for any 10 km box, and the TIFF to JPEG and PNG converter turns its GeoTIFF into an image you can share.

Choosing trees for a changing climate

A Michigan State University researcher received a $500,000 grant to find tree species suited to future Michigan climates, with drought and heat tolerance as the key traits. Portland updated its approved street tree planting lists to include more climate-adapted species, and researchers are asking whether Amazon and Andean trees can be moved to survive climate change. Four major Illinois research institutions have formed a collaboration on urban forest drought resilience, and a Phys.org report found that trees need water and space to deliver the most cooling.

Workforce money and a funding squeeze

West Liberty University was awarded a $1.5 million grant for urban forestry, the Indiana Arborist Association received $250,000 for arborist apprenticeships, and Kentucky State University won $1.2 million. A UNLV program planted 18 trees in a North Las Vegas neighborhood. The target is a shortage of urban foresters, and the money arrives against a backdrop of pruning backlogs and watering challenges on aging infrastructure.

Federal funding retractions are forcing change. Smart Cities Dive reported that tree-planting programs are adapting, and Allegheny County lost millions in green infrastructure grants. Cities are looking at bonds, carbon credits and public-private partnerships, and Illinois EPA funding is available for green infrastructure. Eugene's Urban Forestry Department is planting street trees to reach city climate goals. In Portland, a councilor proposed stripping Urban Forestry's tree regulation team and redirecting the savings toward parks.

Managing tree risk

Risk assessment is leaning on technology too. Ground penetrating radar and aerial drone surveys can reveal structural weaknesses and decay that are not visible to the naked eye. Because tree failure can lead to damage, injury and liability litigation, insurance requirements for tree care professionals are becoming stricter, and standards from the International Society of Arboriculture guide best practice. Purdue's Landscape Report offered tips for managing storm-damaged trees, and the OB Rag covered a condition and failure assessment study of ficus trees.

Pressure on the canopy, and the rules that answer it

Forests and urban tree canopy are still shrinking in the Chesapeake Bay region. Residents in Pensacola protested tree removal while the developer said it is keeping as many trees as it can, and tree cutting at a Ventura project angered residents and put a city pact at risk. Oakland publishes rules for project-related tree removal permits. In Melbourne, a canopy target was called unrealistic under fast-track housing plans. Irvine, Louisville and Asheville are all working on urban forest master plans, though enforcement of tree protection rules varies from place to place.

What city trees return

Studies found that Los Angeles trees capture more carbon than expected. Trees also cool streets and reduce stormwater runoff, and cost-benefit analysis can price those services through avoided carbon emissions and lower cooling energy use. AI-based inventories could make those valuations more accurate, giving planners firmer numbers for budget decisions.

Pests, wood and fairness

Minnesota researchers found fungi that can kill emerald ash borer beetles, and Hawaii reports benefits from biocontrol against invasive species. Ann Arbor and Urban Ashes launched a municipal wood recycling model, a life cycle analysis examined biochar from waste tree stumps, and Philadelphia is trying a new way to fund urban forestry. Rutgers used Dawn Redwoods to revitalize a boardwalk at its gardens.

On equity, the USDA's approach stresses greening without displacement, and research on green gentrification looks at how to add trees without pushing out long-term residents. Colorado environmental justice groups are struggling to keep projects alive after federal cuts, and an online tool reported by the Everett Herald could help local planners increase tree coverage.